/**
 * EduVerse Credentials - Polygon ID SDK模拟工具
 * 
 * 本模块提供了模拟的Polygon ID SDK功能，用于开发和演示目的。
 */

const { v4: uuidv4 } = require('uuid');

// 模拟SDK常量
const DidMethod = {
  PolygonId: 'polygonid',
  Ethr: 'ethr'
};

const Blockchain = {
  Polygon: 'polygon'
};

const NetworkId = {
  Amoy: 'amoy',
  Main: 'main'
};

// 输出确认常量已定义
console.log("模拟SDK常量已定义:", { 
  DidMethod: DidMethod, 
  Blockchain: Blockchain, 
  NetworkId: NetworkId 
});

/**
 * 模拟的数据存储类，用于在SDK未正确初始化时提供基本功能
 */
class DataStorage {
  constructor(storagePath) {
    this.storagePath = storagePath || './data';
    this.data = new Map();
    console.log(`模拟DataStorage初始化，路径: ${this.storagePath}`);
  }
  
  async get(key) {
    return this.data.get(key);
  }
  
  async set(key, value) {
    this.data.set(key, value);
    return true;
  }
  
  async delete(key) {
    return this.data.delete(key);
  }
}

/**
 * 模拟的KeyStore实现
 */
class KeyStore {
  constructor(dataStorage) {
    this.dataStorage = dataStorage;
    this.keys = new Map();
  }
  
  async get(id) {
    return this.keys.get(id);
  }
  
  async set(id, key) {
    this.keys.set(id, key);
    return true;
  }
}

/**
 * 模拟的BJJ提供者
 */
class BjjProvider {
  constructor(keyStore) {
    this.keyStore = keyStore;
  }
  
  async newKey() {
    const id = `key-${Date.now()}`;
    return { id };
  }
}

/**
 * 模拟的内存状态存储
 */
class InMemoryStateStorage {
  constructor() {
    this.states = new Map();
  }
  
  async getGistRoot() {
    return '0x0000000000000000000000000000000000000000000000000000000000000000';
  }
  
  async getGistProof() {
    return { root: '0x0', proof: {} };
  }
}

/**
 * 模拟的凭证存储
 */
class CredentialStorage {
  constructor(dataStorage) {
    this.dataStorage = dataStorage;
    this.credentials = new Map();
  }
  
  async save(credential) {
    const id = credential.id || `cred-${Date.now()}`;
    this.credentials.set(id, credential);
    return id;
  }
  
  async get(id) {
    return this.credentials.get(id);
  }
  
  async list() {
    return Array.from(this.credentials.values());
  }
}

/**
 * 模拟的身份存储
 */
class IdentityStorage {
  constructor(dataStorage) {
    this.dataStorage = dataStorage;
    this.identities = new Map();
  }
  
  async save(identity) {
    const did = identity.did || `did:mock:${Date.now()}`;
    this.identities.set(did, identity);
    return did;
  }
  
  async get(did) {
    return this.identities.get(did);
  }
  
  async list() {
    return Array.from(this.identities.values());
  }
}

/**
 * 模拟的凭证钱包
 */
class CredentialWallet {
  constructor(credentialStorage, identityStorage) {
    this.credentialStorage = credentialStorage;
    this.identityStorage = identityStorage;
    this.credentials = new Map();
  }
  
  async save(credential) {
    return this.credentialStorage.save(credential);
  }
  
  async list() {
    return this.credentialStorage.list();
  }
  
  async get(id) {
    return this.credentialStorage.get(id);
  }
  
  async createCredential(params) {
    const credential = {
      id: params.id || `urn:uuid:${uuidv4()}`,
      type: params.type || ["VerifiableCredential"],
      issuer: params.issuer || "did:mock:issuer",
      issuanceDate: params.issuanceDate || new Date().toISOString(),
      credentialSubject: params.credentialSubject || {},
      credentialStatus: params.credentialStatus || null,
      proof: {
        type: "DataIntegrityProof",
        created: new Date().toISOString(),
        proofValue: "mock..."
      }
    };
    
    await this.save(credential);
    return credential;
  }
}

/**
 * 模拟的证明服务
 */
class ProofService {
  constructor(identityStorage, credentialWallet, stateStorage, circuitsPath) {
    this.identityStorage = identityStorage;
    this.credentialWallet = credentialWallet;
    this.stateStorage = stateStorage;
    this.circuitsPath = circuitsPath;
  }
  
  async generateProof(proofReq) {
    return {
      proof: { pi_a: [], pi_b: [], pi_c: [], protocol: "mock" },
      publicSignals: ["1", "2", "3"]
    };
  }
  
  async verifyProof(proofData) {
    return true;
  }
  
  async transitState(did, oldState, isOldStateGenesis, dataStorage, ethSigner) {
    return { 
      hash: `0x${Math.random().toString(16).substring(2)}`,
      status: 'confirmed'
    };
  }
}

/**
 * 初始化模拟SDK
 * 
 * @param {Object} config 配置对象
 * @returns {Promise<Object>} 模拟的SDK组件集合
 */
async function initMockSDK(config = {}) {
  console.log("初始化模拟SDK...");
  
  // 创建模拟的数据存储
  const dataStorage = new DataStorage(config.dataStoragePath || './data');
  
  // 创建模拟的密钥存储
  const keyStore = new KeyStore(dataStorage);
  
  // 创建模拟的凭证和身份存储
  const credentialStorage = new CredentialStorage(dataStorage);
  const identityStorage = new IdentityStorage(dataStorage);
  
  // 创建模拟的BJJ提供者
  const bjjProvider = new BjjProvider(keyStore);
  
  // 创建模拟的状态存储
  const stateStorage = new InMemoryStateStorage();
  
  // 创建模拟的凭证钱包
  const credentialWallet = new CredentialWallet(credentialStorage, identityStorage);
  
  // 创建模拟的证明服务
  const proofService = new ProofService(
    identityStorage,
    credentialWallet,
    stateStorage,
    config.circuitsPath || './circuits'
  );
  
  // 模拟的身份钱包
  const identityWallet = {
    createIdentity: async (opts) => {
      const did = {
        string: () => `did:${opts.method}:${opts.blockchain}:${opts.networkId}:${Date.now()}`,
        method: opts.method,
        blockchain: opts.blockchain,
        networkId: opts.networkId,
        identifier: Date.now().toString()
      };
      
      const credential = {
        id: `auth-${Date.now()}`,
        type: ["VerifiableCredential", "AuthenticationCredential"],
        issuer: did.string(),
        issuanceDate: new Date().toISOString(),
        credentialSubject: {
          id: did.string(),
          authentication: true
        }
      };
      
      return { did, credential };
    },
    getDID: async (method, blockchain, networkId) => 
      `did:${method}:${blockchain}:${networkId}:${Date.now()}`,
    issueCredential: async (issuerDid, credRequest) => {
      const credentialId = `urn:uuid:${uuidv4()}`;
      const now = new Date();
      
      const credential = {
        '@context': ["https://www.w3.org/ns/credentials/v2"],
        id: credentialId,
        type: ["VerifiableCredential"].concat(credRequest.type ? [credRequest.type] : []),
        issuer: typeof issuerDid === 'string' ? issuerDid : issuerDid.string(),
        issuanceDate: now.toISOString(),
        credentialSubject: {
          id: credRequest.credentialSubject.id,
          ...credRequest.credentialSubject
        },
        credentialSchema: {
          id: credRequest.credentialSchema,
          type: "JsonSchemaValidator2018"
        },
      proof: {
        type: "DataIntegrityProof",
          created: now.toISOString(),
          proofValue: "mockSignatureValue",
          proofPurpose: "assertionMethod",
          verificationMethod: `${typeof issuerDid === 'string' ? issuerDid : issuerDid.string()}#keys-1`
      }
      };
      
      if (credRequest.expiration) {
        credential.expirationDate = credRequest.expiration;
      }
      
      return credential;
    }
  };
  
  console.log("模拟SDK初始化完成，包含必要常量:", {
    DidMethod,
    Blockchain,
    NetworkId
  });
  
  return {
    identityWallet,
    credentialWallet,
    proofService,
    dataStorage,
    keyStore,
    bjjProvider,
    DidMethod,
    Blockchain,
    NetworkId
  };
}

module.exports = {
  initMockSDK,
  DidMethod,
  Blockchain,
  NetworkId,
  DataStorage,
  KeyStore,
  BjjProvider,
  CredentialStorage,
  IdentityStorage,
  InMemoryStateStorage,
  CredentialWallet,
  ProofService
}; 